DEPARTMENT OF DEFENSE INTERFACE STANDARD STANDARDIZED PROFILE FOR ASYNCHRONOUS TRANSFER MODE (ATM)

Transcription

1 NOTICE OF CHANGE INCH-POUND DEPARTMENT OF DEFENSE INTERFACE STANDARD STANDARDIZED PROFILE FOR ASYNCHRONOUS TRANSFER MODE (ATM) TO ALL HOLDERS OF : 1. THE FOLLOWING PAGES OF HAVE BEEN REVISED AND SUPERSEDE THE PAGES LISTED: NEW PAGE DATE SUPERSEDED PAGE DATE vii viii A /50 vii viii New Page New pages 45/46 21 May May May May May RETAIN THIS NOTICE AND INSERT BEFORE TABLE OF CONTENTS. 3. Holders of will verify that page changes and additions indicated above have been entered. This notice page will be retained as a check sheet. This issuance, together with appended pages, is a separate publication. Each notice is to be retained by stocking points until the standard is completely revised or canceled. Custodians: Army - CR Navy - EC Air Force - 90 DISA - DC NSA - NS Preparing activity: DISA (JIEO) DC (Project IXMP-00381) AMSC N/A DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. AREA TCSS

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3 CONTENTS PARAGRAPH PAGE PMD sublayer for E-1 interface DS-1 physical layer interface TC sublayer for DS1 interface PMD sublayer for DS1 interface Satellite physical layer interface ATM layer ATM cell structure and encoding at UNI ATM layer functions ATM layer management functions Preassigned header field values Traffic control and congestion control Signaling ATM Adaptation Layer (SAAL) UNI signaling Connection control Addressing ATM adaptation layer (AAL) AAL AAL AAL 3/ A AAL 3/4 functions and structure AAL 3/4 procedures AAL ATM wide area network (WAN) Physical layer ATM layer ATM cell header format and encoding at NNI ATM layer functions ATM layer management functions SAAL at the NNI ATM network layer Base ATM network Interworking Interworking with non-atm end-systems Interworking with non-atm networks Narrowband ISDN Frame relay networks Internet protocol (IP) router subnetworks Switched multi-megabit data service Base network management Interim local management interface Transaction-oriented application Supersedes page vii of vii

4 PARAGRAPH CONTENTS PAGE 6. NOTES Key-word listing APPENDIX APPENDIX A DoD ATM Addressing Format CONCLUDING MATERIAL FIGURE 1 ATM UNI and Non-ATM Interface Examples of ATM UNIs and Non-ATM Interfaces Base ATM Network B-ISDN Protocol Reference Model Point-to-Point Communications Unidirectional Point-to-Multipoint Communications Profile of ATM Base Standards ATM UNI and ATM NNI Protocol Model: Control Plane for Base ATM Networks Interworking with Non-ATM End Systems Non-ATM End Systems Interworking Across ATM Networks Interworking with Non-ATM Networks N-ISDN Interworking Frame Relay Interworking Example of IP Router Interworking: User Plane SMDS Interworking TABLE I SONET/SDH Signal Hierarchy Supersedes page viii of viii

5 Preassigned header field values. Preassigned virtual path indicator (VPI) and virtual channel indicator (VCI) values reserved for unassigned cells shall be in accordance with AF UNI specification, section Traffic control and congestion control. Traffic control and congestion control shall be in accordance with the AF UNI specification, section Signaling ATM Adaptation Layer (SAAL). SAAL conveys signaling information between layer 3 entities across the UNI. SAAL consists of two parts: a common part and a service-specific part. The service-specific part, called the service-specific convergence sublayer (SSCS), is divided into two sublayers: the service-specific coordination function (SSCF) and the servicespecific connection-oriented protocol (SSCOP). The SSCF shall map the services of SSCOP to the needs of the layer 3 entity, in accordance with ANSI T1.638, sections 7 through 11. SSCOP shall provide assured data delivery for the signaling PDUs by means of selective retransmission, in accordance with ANSI T1.637, sections 6 through 8. SSCOP uses the services of the common part protocol, the SAR and CPCS, which shall be in accordance with ITU-T I.363, section UNI signaling. Signaling at the UNI shall be in accordance with the AF UNI specification, section 5. The signaling function supports point-to-point and point-tomultipoint network connections. ATM signaling permits users on B-ISDN to connect to users on N-ISDN. ATM signaling also permits users on different N-ISDNs to interconnect via B-ISDN (see ) Connection control. Connection at the UNI shall be in accordance with the AF UNI specification. The AF UNI 3.1 specification provides deviations from ITU-T Q.2931, which specifies the procedures for establishing, maintaining, and clearing point-to-point connections at the ATM UNI Addressing. UNI signaling shall support the ICD address format specified in AF UNI specification, section and Annex A. The addressing plan for DoD is presented in Appendix A. For the Defense System Information Network, the numbering plan specified in DCAC , the section titled DSN Worldwide Numbering and Dialing Plan (WNDP), shall be supported. Supersedes page 29 of 29

6 5.2 ATM adaptation layer (AAL). The AAL supports user plane functions and information transfer between and among ATM end systems. Several AAL protocols are available to support different types of users. The AAL is subdivided into sublayers, as shown in Figure 7. The common part (CP) sublayer consists of the segmentation and reassembly (SAR) sublayer, and the common part convergence sublayer (CPCS). The CPCS functions include delineation and transparency of user information, and error detection. The SAR sublayer handles (1) the segmentation of data units so that they can be mapped into fixed-length payloads of the ATM cells, and (2) the reassembly of data units from ATM cells. The SSCS provides the specific service-related functions of the AAL. Variable bit rate (VBR) services include data service for a range of applications from bursty data to compressed video. Constant bit rate (CBR) services include voice and video (circuit emulation). AAL protocols AAL 1-5 for user services are described below AAL 1. AAL 1 shall be implemented in accordance with ANSI T AAL 1 provides a 47-octet user payload, with a 1- octet header to support timing and sequence integrity. AAL 1 supports CBR applications in which a timing relationship is required between source and destination, such as voice or video (circuit emulation). The CBR service clock may be synchronous or asynchronous to the B-ISDN network clock. The normal mode shall be synchronous. Bit count integrity (BCI) shall be ensured in either mode, in conformance with ANSI T1.630, section 9. For the asynchronous mode, clock timing regeneration shall be by adaptive clock recovery as described in AF-SAA , section This method uses local procedures to compensate for jitter, with no timing information carried through the network. Adaptive clock recovery methods are not subject to standardization. AAL-1 shall support circuit emulation for DS1 and E1 for both unstructured and structured data transfer, in accordance with AF-SAA Adaptive clock recovery is not effective against wander (low frequency component to the cell delay variation). For the asynchronous mode, SRTS as defined in 3.4 of AF-SAA may be used where excessive cell delay variation may be experienced AAL 2. AAL 2 supports VBR applications in which a timing relationship is required to exist between source and destination, such as compressed video. This service has not yet been standardized. Supersedes page 30 of 30

7 5.2.3 AAL 3/4. AAL 3/4 supports VBR data transfer. AAL 3/4 shall comply with ANSI T1.629, which defines the SAR and CPCS. AAL 3/4 shall provide message mode and streaming mode service, in both assured and non-assured operations, in accordance with ANSI T1.629, section 6. For non-assured operations, optional error discard allows corrupted PDUs to be delivered to the user. For assured operations, a reliable link protocol is required in the SSCS. For non-assured operations the SSCS is null. Specific AAL 3/4 requirements are given in and New Page 30A

8 APPENDIX A DOD ATM ADDRESSING FORMAT 1.0 Description The following diagram depicts the fields of the DoD ATM NSAP Address format. DoD ATM NSAP Address / \ IDP AFI IDI DSP FI Routing Domain GUI Rsv Area System ID n-s RD1 RD2 RD3 RD4 \ / 2.0 DOD ATM NSAP Field Semantics. IDP Initial Domain Part, an NSAP address structure specified by the International Standards Organization (ISO), contains the subfields AFI and IDI. AFI Authority and Format Identifier, the value of 47 indicates that the IDI part is interpreted as a four decimal digit ICD and that the DSP is represented in binary. IDI DSP New Page Initial Domain Identifier, the ISO assigned the ICD value 0006 to be administered by the National Institute of Standards and Technology (NIST) which has then delegated all authority to the Department of Defense (DoD) under the title USA DoD OSI Network. Domain Specific Part, authority for structure and assignment of DSP values is delegated by ISO to the organization defined by the IDP (in this case, to NIST and then to DoD). The Defense Communications Agency (DCA), renamed the Defense Information Systems Agency (DISA), is the named authority for DoD. The management responsibilities delegated by NIST to DoD require that DoD register the DSP structure for ICD 0006 with NIST. 45

9 FI RD GUI Rsv Area Format Identifier, identifies syntax and associated semantics encoded within an NSAP address. Administrative authority associated with specific FI code points currently applies only to DISA. Routing Domain, uniquely identifies a Routing Domain within the Administrative Domain specified by ICD 0006 and FI. DISA assigns the RD values. RD1 Level 1 Routing Domain, a pre-identified nonoverlapping geographic region, generally not attached to subscriber equipment. RD2 Level 2 Routing Domain, a pre-identified nonoverlapping geographic RD1 subregion, associated with a MAN or concentration of DoD bases. RD3 Reserved for expansion of either the RD2 or RD4 domains. RD4 Level 4 Routing Domain, usually associated with a specific subscriber site. Globally Unique Identifier, uniquely identifies an administration authority for deployed networks. DISA assigns values and delegates authority for the GUI to the Deployed Networks Administration Authority. Reserved for additional semantics or the expansion of the GUI or Area fields. Area, uniquely identifies a subdomain of the RD/GUI, DISA delegates authority for administration and semantic assignment of the Area field to the Deployed Networks Administration Authority or to the Site Administration Authority. System ID System Identifier, identifies a unique system within an Area. n-s NSAP Selector, identifies a direct user of the network layer service, usually a Transport entity. NSAP DSP Field Values and Semantics: Field Value (Hex) Semantic FI 1 Command & Control networks using ATM. New Page 46

10 RD1 00-0f 10-7f Reserved. Major geographic regions such as the Middle Atlantic, Northeast, Southwest, Midwest, Southeast, Northwest, West Coast, Pacific, Europe, and Central/South America ff Reserved RD ff Subordinate geographic region, MAN or concentration of DoD bases. Shall not be further subdivided. RD ff Reserved for expansion of either RD2 or RD4 domains RD ff DISA assigns values sequentially from available space to uniquely identify DISN ATM Service Delivery Point edge switches in RD2 subregions. GUI 00 DISA assigns this value to DISN ATM Service Delivery Point edge switches. 01-0f Reserved. 10-1f Available for subscriber networks in the process of transitioning to DISN Reserved ff DISA assigns values sequentially from the available space to identify an administration authority for deployable networks. The value is globally unique within the FI value equal to 1. Area any value DISA delegates authority over the format and semantic content of the Area field to the Deployed Networks Administration Authority or the Site Administration Authority. The authority is responsible for ensuring uniqueness within an RD/GUI subdomain. System ID any value The authority is responsible for ensuring uniqueness within an Area subdomain. New Page 47

11 n-s any value DISA delegates authority over the format and semantic content of the n-s ID field to the Deployed Networks Administration Authority or the Site Administration Authority for standard acceptable values. New Page 48

12 CONCLUDING MATERIAL Custodians: Army - CR Navy - EC Preparing Activity: DISA (JIEO) - DC (Project TCSS-7110) Air Force - 90 Review Activities: Army - SC Navy - MC, SH, AS Air Force - 02, 13, 17, 19, 93 NSA - NS OASD - IR DMA - MP DIA - DI DLA - DH ECAC Civilian Agency Coordinating Activities: NCS Supersedes page 45 of 49

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